1. Field of the Invention
This invention relates to a method of forming a metal-backed layer and a method of forming an anode.
2. Description of the Prior Art
Cathode-ray tube anodes of conventional color television are formed in the following processes, A glass board having a phosphor screen is suitably surface-treated, then, it is pattern-exposed using a photo-resist of PVA and ammonium dichromate and developed and then, a black material such as, for example, graphite is coated and lifted off thereby to form a black matrix layer. The phosphor pattern formation process is so complex that the coating, drying, exposure, development and drying of a slurry having phosphor pigments dispersed into a PVA-ammonium dichromate photo-resist are repeatedly carried out three times to form respective RGB layers. Furthermore, after the phosphor layers have been formed as above, in order to make a mirror-surface metal film, an organic high polymer layer is coated thereon and then, a metal surface is formed on the organic high polymer layer by, for example, the vacuum evaporation or sputtering technique. Then, the baking process is carried out to degrade the organic materials contained therein to form an anode. Also, a method of forming a metal-backed layer has been disclosed by Japanese Patent Application Laid-Open No. 62 - 185833 (Nissha Printing Co., Ltd.), in which, by use of a transferring body having a metal-backed layer on a releasable base film, is transferred to the face plate of a cathode-ray tube to form a metal-backed layer thereon. However, the transferred metal-backed layer thus obtained did not possess satisfactory characteristics. In addition, in the case of a shadow mask color picture tube, 15 to 20% of an electron beam generally passes through a shadow mask to luminate the phosphor and the other 80 to 85% of the electron beam comes into collision with the shadow mask to increase the temperature thereof, so that the shadow mask can be thermally expanded thereby to deform it convexly to the panel face direction. This phenomenon is called doming. If the oming were occur, the positional relation of the mask holes on the face panel is changed, causing a, in an extreme case, color deviation to take place. Thus, it was necessary to prevent the temperature of shadow mask from increasing.